This dish is called squirrel fish because the fish curls up during frying and, when served with its head on a deep platter, supposedly looks like a squirrel. The recipe recommends tomato ketchup instead of candied Chinese crab apples, which taste like tomato ketchup but require long soaking.
Soak the mushrooms in a small baking bowl with the warm water for half an hour. Pour away the water, cut the stems into small pieces and discard them, quarter the caps.
Blanch the fresh peas and carrot pieces in 7 to 10 min. Drain and rinse when cooled.
Rinse the fish under cold running water and dry inside and out with kitchen paper. Using a kitchen cleaver or heavy, sharp kitchen knife, cut off the head at the junction with the body. Place the head with the underside up and break the skull roof in the middle by a few strong blows with the kitchen cleaver or a heavy kitchen knife. Then flatten the fish head with strong pressure from the palm of the hand. Lay the fish on its side and, without removing the tail, cut it sharply in half along the backbone. Remove the backbone and cut it off at the base of the tail. Score the flesh side of both fillets crosswise at 2, 5 cm intervals almost to the skin. The fish must consist of two fillets joined at the tail.
Mix the above ingredients, oil, water chestnuts, onions, flour, vinegar, salt, garlic